<!DOCTYPE html>
<html>
<head>
    <meta charset='utf-8'>
    <meta http-equiv='X-UA-Compatible' content='IE=edge'>
    <title>Page Title</title>
    <meta name='viewport' content='width=device-width, initial-scale=1'>
    <script src='main.js'></script>
</head>
<style>
.box {
  width: 200px; 
  height: 200px; 
  border-radius: 50%; 
  background: linear-gradient(to right, #333, #fff); 
}
</style>
<body>
  <div class="box"></div>
</div>
</body>
</html>